Did you watch the DVD extras? There's a brief interview about writing the movie and Rogen talks about flipping the various things you expect from a superhero movie. So the "sidekick" is the one that really does everything, the "hero" does not immediately become a fighting machine, the villain has confidence issues and so on.
Which is fine, I suppose, but why do it with an established character? You've already got an uphill battle in selling that idea anyway, now you're doing it with a character that some people expect to be portrayed a certain way. Seems like you're just complicating your own life.
I appreciate the exposure he brought to the character and hope that if he goes on with it, he grows up and brings the same to the character, or that he inspires someone else to do a more traditional version.